Vehicle seatback frames including lumbar supporting panels supported between side members of seatback frame members are relatively common in the art. A typical seatback frame includes generally horizontal upper and lower frame members and a pair of generally vertical side members, the members being connected or continuous at their ends to form a rectangularly shaped frame.
A side panel is attached to central and lower portions of each side member and extends generally forwardly therefrom. Also included is a lumbar supporting panel extending between, and being attached to, lower portions of forward margins of the side panels. One or more resilient members, such as S-shaped springs, extend between, and are attached to, upper portions of the side members.
Attending the use of these conventional seatback frames are a number of problems. For example, following a rear-end collision that forwardly accelerates a vehicle, an associated seatback frame would be accelerated toward a passenger. The mass of the passenger would resist acceleration, resulting in an effective force being rearwardly applied to the lumbar supporting panel. The force would tend to deform the side panels, bending them inwardly toward the passenger and each other and also tending to fold the seatback frame in the same manner. Armrests attached to the side panels would, of course, be displaced therewith and possibly press against the sides of the passenger. The securing and releasing capabilities of a seatback reclining control mechanism mounted to the side panel might, when the latter is deformed, also be caused to malfunction. A similar problem would exist if the passenger sits back suddenly.
In other circumstances, for example, following a front-end collision that rapidly decelerates a vehicle, the head of a rear-seat passenger restrained within the vehicle by a lap belt might continue forward, due to inertia, in an arc described about the belt and strike the upper edge of the lumbar supporting panel of a front seat. Various garnishes and the like have been mounted on seatbacks to cushion this area, but such additions increase the production cost of the seat and the overall weight of the vehicle.
Additionally, depending on the weight, shape and posture of the occupant of a conventional seat, the space between the lumbar supporting panel and the springs could be forced apart to a point where passenger comfort is compromised.
While such seatback frames function with a certain degree of efficacy, none disclose the advantages of the present invention as is hereinafter more fully described.